Just so you know, I think the current model is the 430EX II. I have the 430EX and my main problem with it (from a design perspective) is that the +/- buttons (semi-circles where on the 550 it's a dial) are difficult to press. I had read reviews and thought that it was just people complaining about nothing, but it actually does make a difference when you have to dig your nails in there to press hard to get the settings to change.